Hydroxymethylfurfural (HMF) includes 4-hydroxymethylfurfural (4-HMF) and 5-hydroxymethylfurfural (5-HMF), both of which are multi-purpose intermediates, wherein 4-hydroxymethylfurfural (4-HMF) is a vital pharmaceutical intermediate. Cantharidins are an important class of anticancer drugs having a physiological function of inhibiting protein phosphatase. Cantharidins prepared from 4-hydroxymethylfurfural derivatives show inhibitory activity on PP2B with high selectivity (JP2000309590A). In addition, 4-hydroxymethylfurfural derivatives may also be used to prepare antagonists of prostaglandin receptor EP4.EP4 antagonists may be widely used to treat pain and a lot of other diseases (WO2004067524A1). 4-hydroxymethylfurfural may also be used to prepare antischizophrenic drugs (Tim Sparey, et al., Bioorganic & Medicinal Chemistry Lett, (2008), 18, 3386-3391). 4-hydroxymethylfurfural also has a potential use for synthesizing many useful compounds and new high molecular materials (particularly liquid crystal materials) (Michael J. S. Dewar, Robert M. Riddle, J. Am. Chem. Soc, (1975), 97, 6658-6662) including medicines, resin plastics, diesel fuel additives, etc. On the other hand, 5-hydroxymethylfurfural (5-HMF) may be used to synthesize many useful compounds and new high molecular materials, including medicines, resin plastics, diesel fuel additives, etc., by hydrogenation, oxidative dehydrogenation, esterification, halogenation, polymerization, hydrolyzation or other chemical reactions. Starting from 5-hydroxymethylfurfural (5-HMF), which is regarded currently as the most promising biomass platform molecule, a series of high-value-added products with great market prospect may be synthesized.
4-hydroxymethylfurfural (4-HMF) can only be prepared so far by modification of furan ring using butyl lithium and organosilicon reagents, wherein the reaction is carried out under severe conditions, and the reagents used are expensive. There have been no report to date on the preparation of 4-hydroxymethylfurfural from readily available and cheap chemical raw materials. Meanwhile, 5-hydroxymethylfurfural (5-HMF) is mainly prepared from fructose up to now (James A. Dumesic et al., Science., (2005), 308, 1446; US2008033188). However, fructose is not a rich resource in nature. It has been reported recently that 5-hydroxymethylfurfural (5-HMF) may be prepared from glucose, the most abundant natural carbohydrate (Z. Conrad Zhang et al., Science, (2007), 316, 1597). However, an expensive ionic liquid has to be used as a reaction solvent, and chloride(s) of metal chromium has to be used as a catalyst according to the method. In the above methods for preparing 5-hydroxymethylfurfural (5-HMF), the starting materials are all derived from sucrose or starch, the major food for human beings. As the food crisis goes from bad to worse, it is not an appropriate try to get rid of the oil crisis by manufacturing biofuel from food.
Therefore, it is necessary to find an abundant, readily available, cheap and renewable non-food biomass resource to prepare 4-hydroxymethylfurfural (4-HMF) and 5-hydroxymethylfurfural (5-HMF).